Pneumatic tool



Patented Oct. 20, 1925.

byi

in is provided with a handle 20, in which; a

fluid-pressure supply passage 21, is formed, and a throttle-valve 22 isprovided at the entrance to this passagewhich is controlled by alever23, so that the operator may readiend of the box.

1y control the supply offluid pressure to the tool. d The handle has asleeve part 24 which is screwed onto the upper endof the barrel in suchmanner as to provide or form an annular chamber 25, around the'interiorof the sleeve, and exhaust ports 26, are provided in the sleeve whichopen outwardly to vent said chamber 25. Y I

The upper end of the barrel or cylinder is provided with a verticalannular recess so as toreceive a ring or disk 27 and to also receive thelower end of an annular or cylindrical valve-box 28,the box having itslower. endseated on the upper side of the disk or ring 27 and held downthereon by the clamping action of the handle on the upper As clearlyshown in Fig. 5, of the drawing, the valve-box 28, has an upper centralcylindrical chamber 29, and a lower cylindrical valve-chamber 30 whichlatter. is of a slightly-jlarger diameter than the said upper cham her.and forms an annular shoulder 31, around the base of the upper chamber29 which -for1ns,.in this instance, a stop for the valve on itslip-stroke.

Immediately beneath the shoulder 31, the valve-box is provided with anannular groove 32, and this groove is always in open communication witha series of air-supply or intake-passages 33, which extend vertically inthe wall of the valve-box and whose upper ends communicate with v anannular groove 71 in the handle which latter groove is always incommunication with the fluid-pressure supply; passage-21,- in saidhandle as can be seen In Fig. 1, of the drawing.

It is thus to be understood that when the throttle-valve 22 is'operatedto admit pres from the annular groove 32, and the intake passage 33.This longitudinal passage 34 is provided with a lift-supply port 35,which opens into the valve-chamber 30, and is further provided at itslower end withanother port 36, which also opens into said chamber bothfor purposes that will presently be' explained.

By again referring to Fig. 5, of the drawing it will be noted that theinterior of the These passages 38,.are also clearly shown in Figs. 34and 6 of the drawing.

.Below the lift-ports 37 the valve-box also has a plurality of ports 39,which extend laterally from the valve-chamber and'communicate withvertical passages 40 whose upper ends terminate at a lateral passage'41,which passages 40 extend entirely through the valve-box and open at theouter side of the latter, as shown by broken lines in Fig. 4 of thedrawing.

It is important to. note that the valve-box has also a vertical passage42, whose upper end turns laterally and inwardly and opens on theinterior of the valve-chamber and further that at the upper end of thisvertical passage there is a port 43, which establishes communicationbetween the said passage 42, and at least one of the intake passages 33.As the passages 33, are ,alwayscharged with live air whenever thethrottle valve 22 is open and the tool-is in operation it follows thatunder the same conditions the passage 42 will always be supplied with adiminished amount of air through the relatively small port 43.

By reference to Fig. 6 of the drawing wherein a bottom view of thevalve-box is shown, it will be seen that the lift-passages 38, thevertical passages 40 and the live-air passages 42, all extend to thebottom ofthe box-wall.

On the interior of the box the valvechamber has an annular shoulder 44,which is located above the ports 37, and39 but be neath the lift-supplyport 35 and that this shoulder 44, is produced by a slight enlarge mentof the internal diameter of the valvechamber all of which is for apurpose that will presently be explained.

By further reference to the bottom view of the box in Fig. 6, it will benoted that a blind hole or recess 45, to receive a dowel-pin (not shown)which is utilized to keep the several parts 15-28 and 27 in register, isprovided at the lower edge of the 'wall,and further, that at one side anotch 46, is formed in the lower inner edge of the box wall as bestillustrated in Fig. 5, all for purposes presently to be described.

f Beneath the valve-boxzrndj in the bottom ofthe aniiulerreeess in. theupper end of the cylinder; there is sea'ted a; ring or dish 27; si iownFigsfil fi and 8* the drawihisfring has" a centtali passage 457 an zrnnulm interior channel or gn'oovef48 iil said passage; 2; series ofv-eitic'altliai-t passaig'es 49 enda plurality of} vertieal exhaustpassages 59 the lower ends ofj which lattes extend inwardly and 'openinto the channel or'groove 48 The upper side o'f the ri1-1g o-r disk ispro Vided with' an annular bead -51, which has exterior diameter thatwill enable-it-to enter-the lowene'nd of the valve bo zt when thelatter'is seated thereon, mdat onesid'e; this" head-isvertically 'notched as at52', which notch registers with the notch; 46," in the flower edge;(iftheE Valve-box wail.

A vertical "'fiassa g-e '53, -is provided in" the ring or dish Whose;upper e r-1d communicates Withthe; space i by the notches ek6'52-.(which "in effect form "a port) '=and Whose lower end communicates witha; duct '54; thztt extendsklown in the/Wall of the cylinder 15, and,opens int o' qthe piston.

chamber 16;

live-air passage 42- irr'the valve b'ox has its lower endcommunioetingjwith a; veraticzt-l passage 55, inthe ring or ti'isk andthe lower enct-oit this letter passegefcon-neots with 2r passage 56, inthe 'cylinde'r which opens through the Wall, oif'theoy'linder into thepiston-*chiimber 16. It i x'rii'lltherefore be seen thatthe-entmncefrom} the piston-01mm; berto the? lower nc'i of pa's'sage iifi', lis' ata ,point below the annular exheust -gi oove-48 anti that" Whenever thetiow'e-i enbranee is 'uncoverei 'the plston; 1 7, "Whatevenpres surefluictt'here may bei the piston ch ani piston ehamber whiie'the upp'erends thereof connect with the 'pas'seges9', in the ring or "disk 27.,and also with'the'pessages" 88in 'the valve-box.

By now referring to ,Fig. '9, ofthe drewing it will he noted that "thevalve 5 8"',*i s of the cylindrical type and hzi'se 'cen'ftre1 passage'59, of a' diameter substahtially "equal to the diameter of thepiston-numb r I6,

so that the piston 1'7, "may {reciprocate therethrou'gh. 0n"theexterior, the valve has'txvo annular 'eniergen ents and the formerbeing'si-tuatedabove and spaced "h'oni the latter. 'HieeiilerQement-SOpro- Ewes an "uppe e i l er sh i fl r 6 t moves down.

beir' in -the suite-box 28g and when .p'lawd' I therein forms; an?upper: live air? ohambm fifi on the upper sidaeo of shoulder 62, and;ennule'r spaioer 67 around-ether waive betmeeh the sho'uiders: 631. anct6.4;? anderso-ealhdt nular fliprthmnber beneath; the; shoulden 65; o fthe waive: .I l

' en of 't'iiewalve: hasq nosition beneath the: shoulder"flyinzthe.Value-chem; 1.1": The upper cylindric end 69,.iQf :the vafl ve above theuppermost shoulder 621 thereon serves to: open andtixel'oseg thegennulerjgiooiresoi 18430 edniit tom cutf-ofl' l-ilwej. aim to 01 from the:upper end; of; the. piston )ch wmber through-"the central valuepassag'ee 59; and when this end of thewalwe ris the: dosed position;eel-in Figsg l band-11 1 l of zthe. draw inggv the" groove is; leuti ofiand, the cham; ber' 29; 1 in the upper: end; (iii the; uahiehox will beelo seai egitinst the. ieseapj'e of: pressure so as to. pistononthe-up-stnokea 'Ehe} iower cyiimdrie end 350, of the: value below; thelowve-nmost .1 shoulder L theneon also serves a 5 useful: :puzqgicise inthat? it I coin tro1s' the'ese-ep'e or: pressurezrfrom'"thepistonehemher through the exhaust groove: 48 2+ i opening sa/ii"emhnust as"- .the piston moves upwnd closing. said! exhaust es'thepiston reference to and oi the drawing it will be noted that e-.-smal1iI'poErt -72 zcennects 3 the cylindrical chamber *29 goat the va lve' boxiwiti-r-oneof'the l ive air passeges-3 3 so as to admit'live air:intoithe Tee-r end o'f the vejlveahox *tonthe-puwpose of starting thepiston and valve forward in event theysjhouid both be inigeer-wavrd:position at the' heginning ofqanyf operation of the t-001.

" stroke: I that z is gieater than" its i own :lehgzth and that theinflentioniis especi a/l 'ly useful tools of this class;

- The; operation ofvt'he device is as tie Hens Presu niinglthe Waive. toJoe in thedown or forwzirdrposition shown in IF 1g; 10.. of :the

Edna-Wing end the throttle-Naive openiso that: uidfipnessurezoenzzpessthrough passage 21- M; Likil groove 7i1 ian iethnough supply @1 1intake" 33, the incoming an pnd'clueerai cushion {for the will pass frompassages 33 to annular groove 32 then up over the end 69 of the valveinto the central valve-passage 59 thus acting upon the rear end of thepiston 17 and driving the latter forward in the piston-chamber 16.

During this forward Stroke of the piston the air in the chamber 16, infront of the piston will be exhausted or driven out throughducts 57 toports 39, which latter ports at this time will register with the annularspace 73, around the valve between the shoulders 60 and 61, which spacealso registers Withthe lateral branch 41 of the passage 40 so as toconvey the exhaust through the box-wall to'the annular chamber 25 andfrom which chamber said exhaustescapes by port 26 to the atmosphere.

During this exhaust operation While the piston is making a forwardstroke, the valve 58, is'held down by live air pressure acting upon theupper shoulder 62 and upon the valve end 69.

This holding-down live air pressure is derived from supply passage 33 bypassage 43 to passage 42 and, when the piston 17 has moved down farenough to uncover the lower end of passage 56, live air-pressure fromthe pistonchamber 16, at the rear of the piston will enter saiduncovered end of passage 56, and pass up throughpassages 55 and 42 andwill act in conjunction with the pressure derived from the port 43 onthe upper shoulder 62 of the valve.

When the piston. has moved down far enough in the cylinder to uncoverthe lower end of ductt54 into the piston-chamber behind theforwardly-moving piston, live air pressure from said piston-chamber atthe rear of the piston will enter said duct 54 and pass up topassage 53and notches 46-'-52 to the so-called flip-chamber 68 where it will actupon the lower shoulder 65, 011 the exterior of the valve 58. As thearea of the shoulder 65, is greater than the area of the upper shoulder62, a force will be developed, because of the difference of these areas,that will be suflicient to push the valve 58, up,' the pressures on theopposite rim-ends of thevalve being balanced and the shoulders 63 and 64being subject or exposed to the atmosphere through the port 39.

It is thus to be noted that the. valve 58, will be moved upwardly bylive air-pressure as the piston is making a forward stroke, and has beencompletely shifted to said up or rear position by thetime the piston hasdelivered its blow, and that said valve is held up by live air-pressurefrom port 36 expanding into annular chamber68, by rea- .son" of the factthat the expanded air cannot flow outwardly through the relativelylarger passage 54 as fast as it is supplied. This may be best seen inFigs. 10 and 11.

When the valve 58 has moved upwardly or to its rear position, as shownin Fig. 11 of the drawing, the entrance ,of live air throughannular'groove 32, will be'cut off by the end 69 of the valve extendingup into the box-chamber 29 and live air cannot then pass over the end 69of the valve and enter the rear end of the piston chamber 16, throughthe central valve passage 59.

The valve now being up. or in the rear cut-off position has uncoveredthe annular groove-48 at its lower end 70, and by unco-v ering saidgroove has connected the latter With the piston-chamber 16 and formed acommunication from the piston-chamber through the ports 50 to thepassages 40 and 41 to the annular chamber 25'and ports 26 to theatmosphere so that the pressure at the rear of the piston in thepiston-chamber can escape or exhaust.

At this time lift-supply port 35-, has been connected with lift port 37,by the annular space 73, on the exterior of the valve so that pressurewill be supplied through passages 38 and 49 to ducts 57 into the lowerend of the piston-chamber 16,the annularprojection 61, on the valvehaving closed the exhaust ports 39. v

This lifting pressure through ducts 57,

will be less than the supply pressure in supply passage 21 of the handledue to the relative sizes of the ducts 57, and the passage 35.

The piston 17, 'now having pressure beneath its forward end and airexhausted from the cylinder on top of it, will move up, firstuncovering, with its forward or bottom edge, the; lower end of passage54 thus reducing and providing a relief for the pressure on the bottomshoulder 65 of the valve. After the piston uncovers the cylinder-end ofduct 54 it eflects a covering of the entrance to passage 56, but at thistime the central passage up through the valve, and practically acontinuation of the pistonchamber, is still open to the atmospherebecause groove 48, and ports 50 are uncovered. While the cylinder-end ofpassage 56 is covered by the up or rear-moving piston, live air frompassage 43 to the upper end of passage 42 is building up a pressure inpassage 42 and in the annular chamber 66 with which said passage 42vcommunicates and this live air pressure acts upon the upper or rearshoulder 62, on the exterior of the valve 58, and becomes equal to thesupply pressure in passages 33, at a time predetermined by the size ofpassage 43.

At this moment in the operation, the up per shoulder 62, of the valve isexposed to the pressure building up in annular chamber 66, while thepressures acting upon the shoulders 63,64 and 65 are equalized,therefore when the live air-pressure in passages 56, 55, 42 and in theannular chamber 66 has built up to a greater pressure than that which-isacting upon the shoulders 63-64 "2 In a pneumatic tool=- and of thevalve the latter Will be pushed down or forward by such huil-t-up liveair pressure trompa ssa'ge 43:4,

' When this forward inovement of the" is no pen d; my L w 011 t l PPrear" end" offzthe piston to, repeat the, operation."

Will thus be seen that the valve 58-, is; moved upwardly or rearivardl'yby live airactijng'jon the loiver or fprwardl shoulder 6-5 onthe valvesuch live air passing i-pm he hind: the piston from cylinder "16;": intoduct- 54; and up {to the fii -chamber 68; and the-6- said valve is movedgomv'ardly ordownalsoby liveair which latter live air acts upon the rearor upper shoulder-- 62- and is derived from the passages 33-43 arid lQ;so that both movements of the valve. are efliected; by liveair'pressure' "Having described my invention, what- I 'claimig 'j I a In'a pneumatic tool; having a piston with stroke greater than its-own,length; a valve to control the admission and theIen tire exhaust offluid pressure to andfrom opposite ends of the piston, said vallveh-a-ving a, central' passage 'i-ntp whijch- -the piston enters, saidvalveal'so being provided with differential pness-ure areas;-'a;n'd{means for subjecting the; said difl eren-tial pressuige areas to liveflu-id --pressuneldireeted alter nately from opposite-directions whereby-sai d valve' ivill be 'iilo-ved in both directions by live-fifuidpressure,

having awitlra' StrOke greater-th-an own length a 'valveca-sting,a valve inysaid' casing and having diiferential areas to-c0ntr01the admissionand the entire exhaust of fluidpressure to and from opposite ends of thepiston sai df.differential areas ofithe valve being alternatelysubjected to live fluid pressure "directed freni o ppes in g sidesXvhereby -the valvemay he moved in" both directions by livefluid-press'u-re I alas pneumatic tool 'ha ai eyli nder with pistontherein said v piston haviiiga stroke -'g'i eatenf1than its own "length,a valvecasing, a ya l ve ijn said-casing havingqdtfl'er- 'entlalpressure-surfaees'said valvecontnol- 1 ling theadmi'ssion and the entireexhaustl of fluid pressureto and? from oppositei nds of the piston,means" f orgsubj ectingene off said surfaces tofthe actiono-fliveflili'Ch-PI-BSSHIJB While a relative reduction o-fpressure 0n another ofsaid surfacesis provi'd 'ed, to move the valve in. one direction by liveI pressure, and me ans "Eon subj eatingsaid other surface s a "7 a-"Witha cylinder l ravi n a valve-chamber at of the valve to live fluidpressure whereby to v fiu d'pre sm 1 4. pneumatic to el-lfiavii gapiston;- withxistr'oke greater; than its Owelength, a differential ververto control "the admission" ofmotiv fluid to and" the entire exhaust,ot-f said motive fluid from the -oppsite ends of the piston, said:valve being Inhjved in one di rectiozi by livemotive"fluid*-ii1termittent1y acting on the larger pressure area' ofvalve flat one stroke ofthe pisterniand moved move ie valvein live;

ingthe opposite direct-fonby" live'inoti ve fluid intermittently actingupon the smaller pressure area offthe valveon other" stroke-"0t thepiston.

5. apneurnatic toolhav-ing'a cylinder-g a piston therein withstroke-greater than its: QW'II' length; a val-ye to 'controlthe admiesion and the entire; exhaust'oiii motiye iflu'id to and fromthe oppositeends; of the pistong,

said valve being {located at" the; rearend {of the cylinder 'andin linether ewitliandrneans ffbr intermittently directiinglivemotive-fluidalternately tojo p posing surfacesof the valve and move thesaine indirectibns by live 61in aj'pneumatic toolthe, combination with a;cylinder, offa piston-in; said cy linder said". piston having" a strokegre ater" than its own length; a val vechanl'bei at one end" of thecylinder and havingports and passages therein; for the-- assage oiiilive fli -pressure to' and exhaust the cylinder and -a valfveinsaid-Echamberand m'eved automatioo pally "in Both directions 'hy alternatelybuilt up live air-pressure enaoppo si ng faces 1 of; the valveheliorethe completes: its strokesaid" valveajl eneeebntroll ing theentire exhaust fromtheoppesiteends ofi the cylihderr heumatic tool; thecombination one end thereoii; of" a; piston said cylinder having astroke gi eater than' own 'len gth 1. a valve in said chamber tocentrolthe inlet and the entire exhailst of airg-ssaid valve both ends thereof:whereby vthe piston may move into said passage-pm its return stroke;

return-str cken m 1 -SmIn a; pneumatic-toe]; the combination with acylinder, ofia piston irn saidicylinder having a;stn0l(egneateiithanrits owne length;

iineans at the; end ofsthe: cylinder ton forming a wake-chamber; .saidineans having; ipmgts passages: therein fora-the lnletw andre'xthatiistconstaiittyiopen to: axliye iaiinsuppl-y,

-said{1ive-ain passage havingwone 'endopenihg having a" centralpassagewvhichis opein at a haustfofi fluid pressure,andl-haivingqa'pa'ssage I into the cylinder and also having an open inginto the valve-chamber, and a valve in said valve-chamber, said valvebeing moved in one direction by live air that is builtup in said liveair-passage whilethe cylinder-end of said passage is closed by thepiston and being moved in a reverse direction also by live air saidvalve alone controlling the entire exhaust from the opposite ends of thecylinder. 7 p i I 9. In a pneumatic tool, the combination with acylinder, of a piston in said cylinder having astroke greater than itsown length; avalve-bushing at one end of the cylinder and having avalve-chamber therein, said bushing having alive air passage thatextends from the valve-chamber, communicates with the cylinder and isclosable by thepistonon the return stroke of the latter; means forfeeding live air to said passage while the latter is closed bythepiston, and a valve in said valve chamber movable in one direction bythe live air from said passage and movable in a reverse direction alsoby live air said valve alone controlling the entire exhaust from theopposite ends of the cylinder.

10 In a pneumatic tool, the combination with a cy1inder,oir' a piston insaid cylinder having a stroke greaterthan its own length; avalve-bushing at one endof the cylinder with a chamber thereinand havinga live air-passage extending from said chamber and in communication withthe cylinder, the cylinder-end of said passage' being closable by thepiston; a valve in said bushingchamber having pressuresurfaces ofunequal areas, said valve alone controlling the entire exhaust from theopposite ends of the cylinders; means for feeding live air to said live.

air-passage to act on the pressure surface of the valve having thesmaller area to move the valve in one direction by live air, and

means for subjecting the larger pressure surface of the valve also tolive air to move the valve in a reverse direction.

. 11. In a pneumatic tool having a cylinder with a piston therein whichhas a stroke greater than its own length, a valve bushing :at one end ofthe cylinder; a valve in said bushing with opposing pressure surfaces ofunequal areas, said valve controlling the entire exhaust from both endsof the piston,

said cylinder and valve bushing having passages extending from thecylinder chamber to the said opposing pressure surfaces ofthe 'valve,whereby the piston will serve as a Valve for saidpassages.

. 12. In a pneumatic tool having a cylinder with a piston therein thathas a stroke greater than its own length, a valve bushing, a valve insaid bushing and having o-pposing pressure surfaces of unequal areas v 4said bushing being provided with a passage that extends from thepressure side of one valve-surface and opens into the cylinder and asecond passage that extends from the pressure side of the othervalve-surface'and opens into the cylinder in a plane above the sageopening and may also close the upper passage-opening on its rear stroke.

13. In a pneumatic too-l the combination with a cylinder, of a piston insaid cylinder said piston having a stroke greater than its own length; avalve bushing at one endof the cylinder; a fluid pressure supply a valvein said bushing controlling the entire exhaust of fluid pressure fromopposite ends of the piston, said valvethaving opposingpressure-surfaces of unequal areas; a pas sage which is always open tothe fluid-pressure supply, said passage havingan outlet adjacent one ofthe pressure-surfaces of the valve and another outlet into the cylinder,and a second passage from the cylinder beyond the outlet of thefirst-named passage, said second passage leadingto-and delivering fluidpressure adjacent to another of the valve pressure-surfaces whereby thelatter or second passage may communicate with the cylinder at either theupper or lower sides of the piston while the first-named passage may becut off fromthe cylinder by the piston to shift" the valve from oneposition to another. I I r Y 14:. In a pneumatic tool the combinationwith a cylinder, of a piston in said cylinder said piston having astroke greater than its own length; a valve at one end of the cylinderand havingpressure surfaces of unequal area, said tool having a passagethat extends from the valve-surface of the greater area to a point inthe cylinder where it may be exposed either above orjbelow the pistonaccording to the position of the latter in the cylinder and said toolhaving a second passage that extends from a Valve-surface of I thelesser areato a point in the cylinder nearer the valve than the firstnamed'passage-opening said second passage being cylinder and providedwith exhaust passages; a valve movable in the box to open and close saidexhaust passages and to control the passage of motive fluid to the opposite ends'ot the cylinder,-said valveflhaving a plurality ofpressure-surfaces; a pas- 1 said piston having a stroke greater than itsown length; a valve-box at one end of'said sage that extends from onepressure-surface of the valve to a point in the cylinder where it may beexposed either above or below the piston according to the position of.the piston in the cylinder and a second passage exstroke toward thevalve whereby to permit tending from another pressure-surface of liveair-pressure to build up in said second the valve to a point in thecylinder between passage sufficiently to shift the valve. 10

the first-named passage-opening and the In t sti o y whereof, I afiiX mysignav 5 said exhaust passages said second passage tllrebeing closableat the cylinder opening by the i piston as the latter nears the end ofits JOHN R. L. SANTOS.

